Screw type electric fuse



Oct. 1 2, 1937.

J. J. ANICH SCREW TYPE ELECTRIC FUSE Filed Oct. 15, 1936 Patented Oct. 12, 1937 UNITED STATES PATENT OFFICE Joseph J. Anich, Sault Ste. Marie, Ontario, Canada Application October 15, 1936, Serial No. 105,817

3 Claims.

This invention relates to an electric fuse primarily of the screw type.

It is aimed to provide a novel construction whereby the entire fuse does not have to be dis- 5 carded when blown, and toward this end to provide a fuse wherein the fusible element may be renewed or replaced when desired, and a construction which will enable fusible elements capable of withstanding different loads to be selec- 10 tively used.

Various additional objects and advantages will become apparent from a consideration of the description following taken in consideration with accompanying drawing illustrating an operative 15 embodiment.

In said drawing:

Figure l is a view in side elevation of the improved fuse;

Figure 2 is a central vertical sectional view, on

20 an enlarged scale, taken on the line 2-2 of Figure 1;

Figure 3 is a cross sectional View taken on the line 3-3 of Figure 2, and

Figure 4 is a cross sectional view taken on the 25 line 4-4 of Figure 2.

Referring specifically to the drawing wherein like reference characters designate like or similar parts, If! designates a generally cylindrical block or plug of any suitable insulating material such 30 as Bakelite or porcelain. Anchored on the plug I is a metallic conductor shell II as by means of lugs l2 piercing the block, such shell having screw-threads as at I3 whereby it may be secured removably in an electric socket in the 35 usual manner. Said shell II has a lateral wall I4 extending across the inner end of the plug I0 and provided with a central elongated opening I5.

A U-shaped conductor element I6 has legs I'I passing through longitudinal slots I8 in the plug and the bridge I9 which connects them, is diagonally disposed, as best shown in Figure 4, with respect to the slot I5, so that portions of the bridge I9 will contact the wall I4 on opposite sides of such slot. The terminals of the legs I! are bent laterally and upset at 20 and located in a generally rectangular recess or depression 2| in the outer end of the plug I0.

Removably disposed against the inner end or wall I4 of the shell is a bowed disk 22 of insulation, preferably a flexible sheet, and engaging the same is a conductor cap 23. A tube of conducting material at 24 abuts the inner surface of the cap 23, and passes removably through the disk 22, the bridge I9 and into the plug I0.

55 Passing removably through the cap 23, sleeve 24, and a central opening 25 of the plug is a bolt 26 having a head 21 forming a central contact. A nut 28 of the same width as the groove 2| is removably disposed therein and a screw-threaded portion 29 of the bolt 26 passes therethrough.

A removable and renewable fusible strip 30, of the same shape as the recess 2 I, is disposed therein in contact with the terminals 20 and nut 28. Said fuse may be of any desired resistance, that is, capable of withstanding any desired current, and in practice is usually 110 volts or 120 volts, it being possible to use either of such fusible elements in the fuse.

Said fusible strip 39 is removably held in the recess by an end disk SI of insulation preferably having a roughened or knurled periphery at 32 to facilitate manipulation. Anchored in the disk 3! is a metallic cylinder or nut 32 having interior screw-threads engaged by those at 29 and enabling the disk 3! to be secured tight against the removable and renewable fusible element 30.

It will be realized that the fuse will be screwed into the ordinary socket with the shell II and central contact 27 functioning as usual, the circult passing through the various conductors and in the event of overload, blowing the fuse which may thereafter be renewed or replaced following removal of the disk 3I and blown fuse.

Various changes may be resorted to provided they fall within the spirit and scope of the in- 30 vention.

I claim as my invention:

1. A fuse device of the class described, having a plug provided with an exterior contact and a. central contact, the latter contact being in the 35 form of a bolt, conductors in circuit with said contact including spaced apart elements, said plug having a recess in one end thereof into Which said elements extend, a fusible contact member also disposed in said recess engaging said elements, and means screw-threaded to said bolt disposed over said recess and engageable with said fusible contact member to clamp it against said elements.

2. A fuse device of the class described, having a plug, a shell contact surrounding the same and having a lateral wall opposite one end of the plug and provided with an opening, a U-shaped contact having legs extending through the plug and having a bridge portion diagonally disposed with respect to said opening and engaging said wall on opposite sides of said opening, said plug having a recess, said legs having terminals angularly disposed in said recess, a renewable fusible element engaging said terminals, a central contact in the form of a bolt passing through said bridge and plug, a' nut in said recess through which the bolt passes, a disk, and said disk carrying a nut engageable with said bolt whereby the disk is operable to clamp" the fusible element against said terminals. 7

'3.'A fuse device of the class described, having a plug, a shell contact surrounding the same and having a lateral wall opposite one end of the plug and provided with an opening, a U-shaped contact having legs extending through the plug and having a bridge portion diagonally disposed with respect to said opening and engaging said wall'on opposite sides of said opening, said plug having a recess, said legs having terminals angularly disposed in said recess, a renewable fusible ele- V ment engaging said terminals, a central contactv in the form of a bolt passing through said bridge and plug, a'nut in said recess through which the bolt passes, a disk, said disk carrying a nut'engageable with said bolt whereby the disk is operable to clamp the fusible element against said terminals, a disk of insulation engaging said wall 1 

